// Copyright (c) 2005 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
//
// See scriptaculous.js for full license.

var Builder = {
	NODEMAP: {
		AREA: 'map',
		CAPTION: 'table',
		COL: 'table',
		COLGROUP: 'table',
		LEGEND: 'fieldset',
		OPTGROUP: 'select',
		OPTION: 'select',
		PARAM: 'object',
		TBODY: 'table',
		TD: 'table',
		TFOOT: 'table',
		TH: 'table',
		THEAD: 'table',
		TR: 'table'
	},
// note: For Firefox < 1.5, OPTION and OPTGROUP tags are currently broken,
//       due to a Firefox bug
	node: function(elementName) {
		elementName = elementName.toUpperCase();

		// try innerHTML approach
		var parentTag = this.NODEMAP[elementName] || 'div';
		var parentElement = document.createElement(parentTag);
		try { // prevent IE "feature": http://dev.rubyonrails.org/ticket/2707
			parentElement.innerHTML = "<" + elementName + "></" + elementName + ">";
		} catch(e) {
		}
		var element = parentElement.firstChild || null;

		// see if browser added wrapping tags
		if (element && (element.tagName != elementName))
			element = element.getElementsByTagName(elementName)[0];

		// fallback to createElement approach
		if (!element) element = document.createElement(elementName);

		// abort if nothing could be created
		if (!element) return;

		// attributes (or text)
		if (arguments[1])
			if (this._isStringOrNumber(arguments[1]) ||
				(arguments[1] instanceof Array)) {
				this._children(element, arguments[1]);
			} else {
				var attrs = this._attributes(arguments[1]);
				if (attrs.length) {
					try { // prevent IE "feature": http://dev.rubyonrails.org/ticket/2707
						parentElement.innerHTML = "<" + elementName + " " +
												  attrs + "></" + elementName + ">";
					} catch(e) {
					}
					element = parentElement.firstChild || null;
					// workaround firefox 1.0.X bug
					if (!element) {
						element = document.createElement(elementName);
						for (attr in arguments[1])
							element[attr == 'class' ? 'className' : attr] = arguments[1][attr];
					}
					if (element.tagName != elementName)
						element = parentElement.getElementsByTagName(elementName)[0];
				}
			}

		// text, or array of children
		if (arguments[2])
			this._children(element, arguments[2]);

		return element;
	},
	_text: function(text) {
		return document.createTextNode(text);
	},
	_attributes: function(attributes) {
		var attrs = [];
		for (attribute in attributes)
			attrs.push((attribute == 'className' ? 'class' : attribute) +
					   '="' + attributes[attribute].toString().escapeHTML() + '"');
		return attrs.join(" ");
	},
	_children: function(element, children) {
		if (typeof children == 'object') { // array can hold nodes and text
			children.flatten().each(function(e) {
				if (typeof e == 'object')
					element.appendChild(e)
				else
					if (Builder._isStringOrNumber(e))
						element.appendChild(Builder._text(e));
			});
		} else
			if (Builder._isStringOrNumber(children))
				element.appendChild(Builder._text(children));
	},
	_isStringOrNumber: function(param) {
		return(typeof param == 'string' || typeof param == 'number');
	}
}